Field of the Invention
The invention refers to a mat seal for an electrical connector having a front face, a rear face opposite to the front face and a plurality of passageways each adapted to receive a cable to be inserted through said passageway.
Background
Such a mat seal is, for instance, known from U.S. Pat. No. 6,739,908 B2 disclosing a connector housing including a plurality of terminal receiving chambers, a mat seal mounted to an end surface of the connector housing and a mat seal holder for holding the mat seal wherein the mat seal is disposed between the connector housing and the mat seal holder. The mat seal holder has through holes which are in alignment with the plurality of passageways of the mat seal. Furthermore, the terminal receiving chambers of the connector housing are also aligned with the plurality of passageways of the mat seal. In order to mount terminals into the terminal receiving chambers of the connector housing the terminals first are connected, for example by a crimping process, to a cable and the so connected terminal with cable is inserted through the through holes of the mat seal holder and through the passageways of the mat seal into the terminal receiving chambers of the connector housing. One general object of a waterproof electrical connector is to have a good sealing ability of the mat seal, in particular around the cables which are accommodated within the passageways of the mat seal when the terminals are completely inserted into the terminal receiving chambers of the connector housing. Also it has to be ensured that the insertion force to insert the terminals and the cables through the mat seal is low with a low risk of damaging both the mat seal and the wires, in particular the connection between the cables and the terminals, during the insertion process.
Another mat seal is described in WO 2009/075850 A1 disclosing a mat seal having a thick portion and a thin portion. The mat seal is provided with broad passageways within the thick portion and with narrow passageways within the thin portion. This mat seal is, therefore, suitable for electrical connectors accommodating terminals and cables with different sizes.
A trend, in particular in the automotive industry, is to push weight and cost reduction for wire harnesses. Car manufactures are focusing to use smaller cables. Smaller cables necessitate mat seals having passageways with smaller diameters in order to guaranty sufficient sealing abilities. However, smaller cross section diameters increase the risk of cables being buckled during insertion through the mat seal. In addition, due to the very small diameters of the cables there is a risk that during the insertion of the terminal and the cables through the mat seal the cables are damaged or torn off from the terminal.
Using smaller terminals and smaller cables makes it possible to reduce the distance between adjacent terminals. This may results in difficulties when manufacturing the mat seals. The passageways are typically produced by injection molding tools having cores wherein the cores are forming the passageways through the mat seal. The thinner the passageways have to be formed the thinner the cores have to be. This results in a high risk of the cores being broken during the manufacturing process, for example, during the retraction of the cores out of the molded mat seal.